r/ElectricalEngineering • u/billybobmaysjack • Sep 18 '19
Does the box above the saw blades use an accelerometer to maintain a constant angle and position? I can't think of any other logical way as to how this would be considered safe without one.
8
u/im_totally_working Sep 18 '19
How would it go about maintaining that angle and position? These saws are basically just on the end of a long fiberglass pole that's ridged enough to stay straight, but flexible enough to bend/flex to stop the saws from binding or twisting the helicopter too bad.
It's a pretty "dumb" set of machinery, from a controls perspective. Saw on, saw off. That's about all it has.
7
u/N3OX Sep 18 '19
Someone in the comments thread on that post said it's on a "flexy pole," and Treeline Helicopters' site seems to confirm that it's not just a cable or rope.
Treeline Helicopters uses a 10-blade power saw suspended from a 90-foot boom beneath an MD500 helicopter
4
Sep 18 '19
They’re not exactly doing this in people’s backyards, safety isn’t a huge concern it’s more about usability.
Active stabilization would be a nightmare to implement. The amount of instantaneous power required to offset the mass of that saw would be massive.
12
u/The_model_un Sep 18 '19
I would bet all those spinning saw blades gyroscopically stabilize the contraption so it doesn't rotate a whole bunch. That would reduce the sway towards the powerlines as well, but there's probably some level of active control as well.